Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations mark it read-only and open-world. The description adds that it uses k-Anonymity, implying privacy-preserving behavior, and states the return value (breach count). This goes beyond annotations without contradiction.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two concise sentences that front-load the main action and return value, then provide usage guidance. No wasteful wording.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter read-only tool with no output schema, the description adequately covers what it does, returns, and when to use it. No output schema means the 'Returns breach count' is sufficient.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema fully covers the single parameter with 'Password to check' (100% coverage). The description doesn't add additional constraints like hashing or format, so it meets the baseline but no extra value.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'Check if a password has appeared in known data breaches using k-Anonymity' and specifies it returns a breach count. This distinguishes it from sibling tools like dev_password_generate or other lookup_* tools by focusing on breach verification for passwords.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides a clear usage context: 'Use when you need to verify password safety.' It doesn't explicitly name alternatives or when not to use, but the tool's purpose is unique enough that the context is sufficient.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.